Air purifier



June 27, 1950 GILMORE 2,512,930

AIR PURIFIER Filed Jan. 25, 1947 gwmm 19a L iii/r201! Patented June 27, 1950 2,512,930 I AIR PURIF'IER -llarry L. Gilmore, Adrian, Mich., assignor to Aget .Manufacturing Company, Adrian, Mich., a corporation of Michigan I I Application January 25, 1947, v Serial No. 724,284

1 Claim, (01. 51-273) This invention relates to the direct. removal of' airfrom tools acting to remove particles from the "work, as 'in"dental laboratories, and such abrading, dressing, polishing and analogous grinding operations.

This invention has utility when incorporated in a bench-providing unit having a particle intake down passage to a chamber with an updraft from the chamber to a filter bag. A suction fan acts upon the exterior of the bag.

Referring to the drawings:

Fig. l is a front View, with portions broken away, of an embodiment of the invention in a dental laboratory bench unit;

Fig. 2 is a view from the left of Fig. 1, with parts removed to show the general air flow directions;

Fig. 3 is an end elevation from the right of Fig. 1, with the screened air-spill outlet sufficiently cleared to show the fan operating motor and centrifugal fan housing and Fig. 4 is a fragmentary view in perspective of the top of the bag filter.

A main cabinet or housing I, has a top deck or support 2, upon which is located a pair of hoods 3. A rim 4 provides a rim or pan region for a coarser particle receiver 5 with the deck 2 as its floor extending back under the hood 3 to a baflie 6. Ends I support the arch top hood 3 therebetween with an arc clearance 8 back from a shield extension 9 forward and downward from the hood 3. On the support 2 between the hoods 3, may be a motor I having a shaft II, extending into the clearance 8 to carry grinding wheels or the like I2, I3, under the respective hoods 3. The baflle 6 has narrow clearance sides I4 upward from the support 2, with a connecting narrow clearance I across the top of the baflie 6.

The restricted intakes I4, I5, under the hoods 3, have therefrom downward in the back of the housing I a passage I8 formed between the housing I back wall and an inner parallel partition I! extending vertically upward from a lower horizontal partition or deck I8 to the support or upper deck 2. The down passage I6 has an opening I9 thru the deck I8 to a settling chamber 20 in the housing I below the deck I8. The down passage I6 is the full extent of the back length of the housing I, so that from each hood 3 there is suction draft to the chamber 20.

The deck I8 has an opening 2I bounded by a rim 22 anchoring an upwardly extending warp and woof fabric bag or foraminous flexible wall filter 23 forming a chamber 24 having a top 25,

diametrically engaged by clips 26 frdmdeperiding end arms 2T'of a cross bar '28; The crossbar28, medially of its extent has a connection 29 to an actuator shaft 30 mounted at one end in the partition I1 and at its other end protruding thru the front wall of the housing I with 2. depending handle or rocker crank 3|. The clearance downward from the underside of the support or upper deck 2 is sufficient for but a slight angle of rock for the shaft 30, so that the lifting of one end of the bar 28 may not pull the filter or bag loose from the rim 22. Snap or quick pulls in the rocking of the shaft 30, stretches taut one side of the filter 23, and slacks the opposite side. A repetition of this teetertottering operation of the bar 28 brings about a rather vigorous shaking of the filter 23. The fine particle laden air rises from the settling chamber 20 into the chamber 24. The air escapes thru the filter wall 23, where these fine particles or dust accumulate on the inner side of the filter wall 23. Upon oscillation of the crank handle 3I, this dust is shaken off the filter inner wall side to drop into the settling chamber 20. A means is thus provided for quickly and easily retaining filter air flow capacity against particle clogging.

A chamber 33 is in the housing I surrounding the filter bag 23. The partition 32, between the decks 2, I8, has an opening 34 therein, with a bowed bar means 35 as an openwork to prevent any slackening of the filter 23 of an extent for such to be drawn into the opening 34 to a housing 36 for a centrifugal fan 31 directly connected to a motor 38 on a base 39 mounted on the partition I8. The fan and motor unit are in a plenum chamber or mufller section 40 as a portion of the housing I provided at the opposite side of the partition 32 from the chamber 33. The scroll housing 36 for the suction fan 3'! has a discharge 4I into the chamber 40. The housing I oppositely from the partition 32 has a screen section 42 as a spill opening for the purified air to escape from the chamber 40.

Conveniently for the operator of this bench unit, the front wall of the housing I, just beneath the deck 2 and at the upper region of the chamber 33 has a switch 42' for cutting the motor, 38 inand out. Adjacent the switch 42' is a drawer 43, which may provide means for placing work to receive attention, as well as upkeep items for the equipment.

The suction fan 31 when operated to draw in air at a velocity of 2000 ft. per minute thru the inverted U-shaped intake I4, 15, I4, underv ing ;a back wall con the hood 3, may have the pull or suction outside the filter 23 in the chamber 33 in the range of 1.2 inches of water below atmospheric pressure.

The down pitch forward end of the pan or receiver 5 is of advantage, for the operator may readily scoop or brush out particles which have accumulated therein The deposit, of. particles in the settliniclian'iherjfl, may be; rrnOyed1py releasing clips 44 and taking off a door 45, from its sealed assembly.

The air flow thru the;

chamber 40 provides a cooling draft for the motor 38.

What is claimed and it is desired to secure by; Letters Patent is:

An air purifier bench unit comprising a support having a down-draft,taliewif passage therefrom, a, rotary grindingwneer'worearned by the support, a hood rising from the support, said hood having an ,jgxtension including an rerllae iie s ee i9 eesunner helm! L\ all mgeive 0 20 to the support, and a bafiie rising from the sup- REFERENCES CITED iiTheifollowing references are of record in the fil'e"ofi this patent".

s'TATEs PATENTS Name Date reggae Mueller May 20, 1913 1,177,342 Leiman Mar. 28, 1916 ,1,52,s, 9 r. 3, 193-5 

